This invention pertains to the field of security bags or pouches for carrying money or other valuable items. More particularly, the invention concerns a security bag having a tamper evident closure.
Businesses frequently transmit money or other valuables to other businesses and to banks. Often, these businesses will use a canvas deposit bag that is provided with a lock and key in order to secure the contents of the bag. In recent years, the canvas bag has been replaced with security pouches or bags composed of flexible plastic or polyester that exhibit the same strength characteristics as the canvas bags. Rather than a lock and key, these plastic bags use a number of adhesive strips mounted on a closure flap that is folded over the opening of the bag to close and seal the bag. The plastic bags of the prior art are tamper resistant in the event that the closure flap is pulled apart from the opening of the bag because the plastic bag material distorts and tears at the Portions where the adhesive attaches the flap onto the bag.
However, one difficulty with these plastic bags is that the closure flap can be readily and cleanly disengaged when subject to very cold temperatures. For instance, when the closure flap and adhesive is exposed to a Freon gas, the flap can be pulled away from the bag opening without leaving any evidence that the flap has been opened. Consequently, there is a need for a security bag or pouch that uses a closure flap that provides a permanent visible indication that the bag has been tampered with, even when the flap has been opened without distortion of the bag material.